1. From the Robert M. Berne Cardiovascular Research Center (I.A.M.B., M.E.G., L.J.D., S.A.M., B.E.I.)
2. Cardiovascular Research Laboratory, Division of Cardiology, Pneumology and Angiology, Medical Faculty, Heinrich Heine University, Dusseldorf, Germany (L.D., M.M.C.-K.)
3. Department of Pharmacology (L.J.D.)
4. Lillehei Heart Institute (J.L.H.)
5. Division of Cardiology, Department of Medicine (J.L.H.), University of Minnesota, Minneapolis
6. American Heart Association, Dallas, TX (J.L.H.).
7. Division of Nephrology, Department of Medicine (T.H.L.)
8. Department of Molecular Physiology and Biophysics (B.E.I.), University of Virginia School of Medicine, Charlottesville